How to create private network with preallocated amount of ETH?

Question

I am trying to create a private network for testing purposes. What I need is:

1. Fast generating of DAG file.
2. Fast mining of the first block.
3. Address with some preallocated amount of Eth.

I found that this could be done by two ways, the first one is:

• Generate the address.
• Pass it in the genesis file.
• Run geth --datadir "." init genesis.json

• Run geth --dev --mine --datadir "."

  PROBLEM: Address is not preallocated with money (I don't know why, maybe genesis.json file isn't reading properly)

The second one is:

• Generate the address.
• Pass it in the genesis file.
• Run geth --datadir "." init genesis.json

• Run geth --networkid 123 --nodiscover --mine --maxpeers 0 --datadir "."

  PROBLEM: DAG file is generating too slow.

Q: Any suggestions how I can meet all requirements?

genesis.json:

{
  "nonce": "0xdeadbeefdeadbeef",
  "timestamp": "0x0",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "extraData": "0x0",
  "gasLimit": "0x8000000",
  "difficulty": "0x01",
  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "coinbase": "0xe7b728f368fce77508e4562ef370d3e902bb79dc",
  "alloc": {
    "0xe7b728f368fce77508e4562ef370d3e902bb79dc": {
      "balance": "10000000000000000000"
    }
  }
}

geth info:

Geth
Version: 1.4.3-stable
Protocol Versions: [63 62 61]
Network Id: 1

Answer 1

The first one will work,

Once you’ve generated your account, quit geth with and remove every folder except keystore/ from your datatir:

$ cd <your datadir>
$ rm -rf `ls | grep -v keystore`

update your genesis block json, adding the following to the alloc key:

"alloc": {
    "<your account address e.g. 0xcc8C048426978c5877212281b8a75F1B4E71a862>": {
        "balance": "10000000000000000000"
    }
}

Now re-run the geth command using the newly updated genesis json file and the same datadir, when you check your account balance you will find you now have 10 ether:

Check completes steps in my blog lightrains.com

Answer 2

The easiest way to do this is with testrpc, it is way faster and has some nice developer features. I struggled with the genesis thing a bit, and just used this:

Install testrpc with: npm install -g ethereumjs-testrpc

Run testrpc like this:

testrpc -a "10" --seed "2553" --debug --account="<acct number>, <amount of wei in hex>" --account="<another account>,<some amount>"